Update to the 2014 NEC Changes for PV Presented at the Solar ABCs Stakeholder Mee<ng San Francisco, CA July 11, 2013 Ward Bower Ward Bower Innova<ons LLC wibower@centurylink.net
INTRODUCTION The 2014 Na&onal Electrical Code A VERY BUSY CODE CYCLE LOADED WITH CHANGES! This Cycle s Change Process was VERY complex Today s presenta<on focus s on New and Changed PV installa<on requirements The most significant changes were centered on SEIA/Solar ABCs supported changes A few less significant changes are listed Impacts of some of the changes (economics, reliability, hardware) are briefly discussed
The Busy 2014 NEC Cycle The NEC is revised every three years. Proposals come from VARIED AND MANY sources. 2014 Ar<cle 690 and 705 proposals came primarily from: Solar Energy Industries Associa<on. PV Industry Forum with Solar ABCs Standards Groups (NRTLs, IEEE, Firefighters, Task Groups, AHJ Orgs, Manufacturers, Systems Providers.) Process involves Proposal submihals and Public Comments
ACKNOWLEDGEMENTS SEIA (John Smirnow) Sponsors WB and BB Bill Brooks Brooks Solar and my alternate John Wiles SWTDI and Secy. Industry Forum Larry Sherwood Solar ABCs Tim Zgonena UL workshop host/member CMP4 Ronnie Toomer Chair CMP4 PV Industry Manufacturers, systems designers/ installers, AHJs, u<li<es, (and more) CMP4 members and NFPA staff etc.
The 2014 NEC By the Numbers 223 Proposals for 690 & 705 Several major proposals to reorganize 690 Included Fire (first responder) NFPA Task Group Resulted in 10 Panel proposals from panel- appointed task groups The ROP contained some very conten<ous language and removed the bahery sec<on Resulted in SEIA and Solar ABCs weekly conference calls and a workshop that further appointed 14 industry task groups to provide public comments. (PV industry responded!) SEIA priori<zed 5 topics that were submihed by SEIA along with the industry forum and others 88 Public Comments were submihed Mul<ple TCC Comments were submihed to clarify reorganiza<on and panel proposals Faults, Arcs, Fire Were Major Topics. Reorg was a major confusion factor
NEC PV Related Defini<ons Green: Underline is New or Change, Red Cross- out is Deleted, Black is Current Code, Blue indicates a move AC Module Array Bipolar PV Array Blocking Diode (Def. only) Building Integrated PV Charge Controller- (Diversion) Hybrid System(Moved) Interac<ve System Inverter Inverter Input Circuit Inverter Output Circuit Module Monopole Subarray Ward Bower Innovations Panel Photovoltaic PV Output Circuit Photovoltaic PV Power Source Photovoltaic PV Source Circuit Photovoltaic PV System Voltage Solar Cell Solar Photovoltaic System Stand- alone System Electrical Prod. and Dist. Net Direct Current (DC) Combiner DC- DC Converter Mul<mode Inverter 6
The Parts of Ar<cle 690 Green indicates Significant 2014 Changes Part I (1-6) General (Definitions )- Reorg (New) Part II (7-12) Circuit Requirements (Reorg/New 1000V) Part III (13-18) Disconnecting Means (Major Reorg) Part IV (31-35) Wiring Methods (Major Reorg, and New) Part V (41-50) Grounding (Some New, Some Revised) Part VI (51-56) Marking (Some New) Part VII (57-64) Connection to Other Sources Part VIII (71-74) Storage Batteries (Reinstated with changes after attempted move to 480 was dropped) Part IX (80-85) Systems Over 600 Volts (Note the Proposals for EV Charging Rejected) Ward Bower Innovations 7
690.4 Installa<on General Requirements- (Major Reorg) 2011 NEC A. Photovoltaic Systems B. Iden8fica8on and Grouping 1) PV Source Circuits (Moved) 2) PV Output & Inverter Circuits 3) Conductors of Mul8ple Systems 4) Grouping C. Module Connect Arrangement D. Equipment E. Wiring and Connec8ons F. Circuit Rou8ng G. Bipolar Systems H. Mul8ple Inverters 2014 NEC A. Photovoltaic Systems B. Equipment C. Qualified Personnel D. Mul<ple Inverters Excep&on. A directory shall not be required where all inverters and PV dc disconnec&ng means are grouped at the main service disconnec&ng means. Most of what is missing went to 690.31 (Wiring Methods) Ward Bower Innovations 8
690.5(A) Ground- Fault Detec<on and Interrup<on. Grounded dc photovoltaic arrays shall be provided with dc ground- fault protec8on mee8ng the requirements of 690.5(A) through (C) to reduce fire hazards. Ungrounded dc photovoltaic arrays shall comply with 690.35. The ground- fault protec<on device or system shall: (1) Determine the PV input circuit has isola<on prior to export of current, (Many Variables in USA Systems) (1) Be capable of detec<ng a ground- fault in the PV array dc current carrying conductors and components including any inten<onally grounded conductors (2) Interrupt the flow of fault current, (3) Provide an indica<on of the fault, and (4) Be listed for providing PV ground fault protec<on.
690.7(C): PV Source and Output In one and two- family dwellings, PV source circuits and PV output circuits that do not include lampholders, fixtures, or receptacles shall be permihed to have a maximum PV system voltage up to 600 volts. Other installa<ons with a maximum PV system voltage over 600 1000 volts shall comply with Ar<cle 690, Part IX. This is in response to NFPA High Voltage Task Group work to change the Voltage Threshold Level throughout the NEC from 600V to 1000V.
690.11. Arc- Fault Circuit Protec<on (Direct Current) Photovoltaic systems with dc source circuits, dc output circuits, or both, on or penetra<ng a building opera<ng at a PV system maximum system voltage of 80 volts or greater, shall be protected by a listed (dc) arc- fault circuit interrupter, PV type, or other system components listed to provide equivalent protec<on. The PV arc- fault protec<on means shall comply with the following requirements: (1) The system shall detect and interrupt arcing faults resul<ng from a failure in the intended con<nuity of a conductor, connec<on, module, or other system component in dc PV source and output circuits. (2) The system shall require that the disabled or disconnected equipment be manually restarted. (3) The system shall have an annunciator that provides a visual indica<on that the circuit interrupter has operated. This indica<on shall not reset automa<cally.
First Solar Agua Caliente 290MW How does arc- fault protec8on requirements fit a 3miX4mi PV array
690.12 Rapid Shutdown of PV Systems on Buildings. PV system circuits installed on or in buildings shall include a rapid shutdown func<on that controls specific conductors in accordance with 690.12(A) through (D). (A) Requirements for controlled conductors apply only to PV system conductors of more than 1.5 meters (5 feet) in length inside a building, or more than 3 meters (10 feet) from a PV array. (B) Controlled conductors shall be limited to no more than 30 volts and 240VA within 10 seconds of rapid shutdown ini<a<on. Voltage and power shall be measured between any two conductors and between any conductor and ground. (C) The rapid shutdown ini<a<on methods shall be labeled in accordance with 690.56(B). (D) Equipment that performs the rapid shutdown shall be listed and iden<fied.
690.12 Does Not Reduce Array Voltage for Firefighters Challenge for the Future: Make Module Level Disconnect Hardware Reliable and Economical for Future Installa<ons
690.12 Rapid Shutdown of PV Systems on Buildings. The area within the 10 boundary of the array is not reduced voltage Conductors more than 5 feet in length inside a building, or more than 10 feet) from a PV array are covered by 690.12 Ward Bower Innovations 15
690.35(C) Ground Fault Protec<on in Ungrounded PV Systems All photovoltaic source and output circuits shall be provided with a ground- fault protec<on device or system that complies with (1) through (4): (1) Determine the PV input circuit has isola<on prior to export of current (1) Detects ground fault(s) in the PV array dc current carrying conductors and components (2) Indicates that a ground fault has occurred (3) Automa<cally disconnects all conductors or causes the inverter or charge controller connected to the faulted circuit to automa<cally cease supplying power to output (4) Be listed for providing PV ground fault protec<on
690.41. System Grounding 690.41. For a photovoltaic power source, systems shall comply with 690.35, or one conductor of a 2- wire system with a photovoltaic system voltage over 50 volts, but not greater than 300 volts, and the reference (center tap) conductor of a bipolar system shall be solidly grounded or shall use other methods that accomplish equivalent system protec8on in accordance with 250.4(A) and that u8lize equipment listed and iden8fied for the use. 690.41. System Grounding. Photovoltaic systems shall comply with one of the following: (1) Ungrounded systems shall comply with 690.35 (2) Grounded 2- wire systems shall have one conductor grounded or be impedance grounded, and the system shall comply with 690.5 (3). Grounded bipolar systems shall have the reference (center tap) conductor grounded or be impedance grounded, and the system shall comply with 690.5 (4) Use other methods that accomplish equivalent system protec<on in accordance with 250.4 (A) with equipment listed and iden<fied for the use.
More (but not all) Significant 2014 NEC Changes Other Significant Changes Include: 690.13 (Disconnects) and 690.15 (Disconnects of PV Equipment). Total Reorganiza<on with the elimina<on of 690.14 (Addi<onal Provisions) 690.17 (Switches and Circuit Breakers) 690.31 (Wiring Methods etc.) 690.47 (Grounding) (Auxiliary Electrodes) Chapter VIII (Bahery Systems) Reinstated 705.12 (Bus/Conductor Ampere Ra<ngs)
Summary (2014 NEC) The PV industry provided excellent input to maintain economically & safe PV installa<on requirements There were many changes and technology improvements with needed advanced func<onali<es for PV systems are coming. (VAR support, voltage regula<on, ride through, frequency support, microgrid, smart grid) Module level safety measures didn t make it in 2014 (but Technology CHANGE will likely lead to new applica<ons with high reliability) Industry Par<cipa<on was high and con<nues to be HIGHLY ENCOURAGED The 2014 NEC cycle provided several cri<cal posi<ve clarifica<ons and advances for the PV industry.
Thank You! The Changes in the 2014 NEC related to PV systems and DG interconnects are just a start! Smart Grid interconnec8ons are coming Demand response Is here Micro- grids are here Hybrid systems DGs are?? Challenges and Opportuni8es Exist! Ward Bower Innovations 20